Lead Architect - NIS

Southern Water; Worthing; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Company and performance-related bonus

Generous pension

Life assurance payment equal to four×;

Health benefits through a Cash Plan

Two paid community volunteering days a

28 days annual holiday

Occupational health service

Retail discount app

Maternity leave and flexible return to

Job summary

Southern Water seeks a Lead Architect to own the end-to-end architecture for the NIS programme, spanning OT, IT, data and security. Hybrid working in Falmer/Durrington with 37 hours per week and a salary dependent on experience.

You will define governing architecture, drive crucial design decisions, and ensure compliance with enterprise standards and regulatory requirements across OT and IT landscapes.

Qualifications

• Significant experience designing and governing OT and industrial control systems.
• Strong knowledge of SCADA, PLC, DCS, RTU, HMI and historian technologies.
• Experience with OT cybersecurity standards IEC 62443, NIST, ISO 27001 and NIS requirements.
• Experience integrating OT platforms with enterprise IT, cloud, data and monitoring solutions.
• Proven leadership of architecture across complex programmes or transformations.
• Excellent stakeholder engagement, governance and decision-making skills.

Responsibilities

• Lead architecture across a complex, business-critical programme.
• Define and maintain end-to-end architecture roadmap and key design decisions.
• Ensure alignment across OT, IT, security, data and technology domains.
• Establish and chair architecture governance and design assurance activities.
• Review and challenge designs from internal teams, system integrators and vendors.
• Identify and manage architectural risks, dependencies and cross-programme impacts.
• Work closely with programme leadership to align technology with business outcomes.
• Act as primary architectural advisor for stakeholders across the programme.

Skills

OT architecture

OT governance

Stakeholder engagement

Architecture leadership

Security integration

Education

TOGAF or equivalent architecture certification

CISSP

CISM

GICSP

ISA/IEC 62443

Tools

OT networking

Purdue Model

Job description

# Southern Water## Lead Architect - NISApply: Worthing: Brighton: Posted Today: End Date: November 11, 2026 (13 days left to apply): JR9197**Closing Date**2026-12-01**Job Title: Lead Architect - NIS Programme****Location:** **Falmer or Durrington – Hybrid working (2 days a week)** **Hours:** **37 hours per week****Salary: depending on skills and experience**We're looking for an experienced **Lead Architect** to play a pivotal role in one of our most significant operational technology transformation programmes.As the architectural lead for our NIS programme, you'll be responsible for defining and governing the overall technology architecture, ensuring solutions across Operational Technology (OT), IT, data, security, and integration are aligned, secure, and fit for purpose. You'll act as the key architectural authority, providing technical leadership, driving design decisions, and ensuring compliance with enterprise standards and regulatory requirements.**What will you be doing?*** Lead architecture across a complex, business-critical programme.* Define and maintain the end-to-end architecture roadmap and key design decisions.* Ensure alignment across OT, IT, security, data, and technology domains.* Establish and chair architecture governance and design assurance activities.* Review and challenge designs from internal teams, system integrators, and third-party vendors.* Identify and manage architectural risks, dependencies, and cross-programme impacts.* Work closely with programme leadership and delivery teams to align technology decisions with business outcomes.* Act as the primary architectural advisor for stakeholders across the programme.**What are we looking for?**We're seeking a highly experienced architect with a strong background in Operational Technology environments and large-scale transformation programmes.**You'll bring:*** Significant experience designing and governing OT and industrial control system environments.* Strong knowledge of SCADA, PLC, DCS, RTU, HMI and historian technologies.* Experience of OT networking, segmentation, firewalls and Purdue Model principles.* Understanding of industrial protocols such as OPC-UA, Modbus/TCP, DNP3, PROFINET and Ethernet/IP.* Strong knowledge of OT cyber security standards including IEC 62443, NIST, ISO 27001 and NIS requirements.* Experience integrating OT platforms with enterprise IT, cloud, data and monitoring solutions.* Proven experience leading architecture across complex programmes or business transformations.* Excellent stakeholder engagement, governance and decision-making skills.**Desirable*** TOGAF or equivalent architecture certification.* Security certifications such as CISSP, CISM, GICSP or ISA/IEC 62443.* Experience working within regulated, critical infrastructure, utilities, energy or transport environments.**Why Join Us?**This is an opportunity to shape the architecture of a major transformation programme that underpins essential services for our customers and communities. You'll work alongside senior stakeholders, influence strategic technology decisions, and help build secure, resilient and future-ready operational technology environments.At Southern Water, we're committed to creating an inclusive workplace where everyone can thrive, bringing their authentic selves to work and contributing to meaningful change.### Interested in the role?* We reserve the right to close this advertisement early if we receive a high volume of suitable applications, so if you are interested in the position please do send your application over today to ensure consideration.* We truly appreciate every application. Please note, that due to the volume of interest, we may not be able to provide personalised feedback to all applicants.### Our Benefits* Company and performance-related bonus* Generous pension* Life assurance payment equal to four times your annual salary* Health benefits through a Cash Plan* Two paid community volunteering days a year* 28 days annual holiday* Occupational health service* Retail discount app* We offer competitive maternity leave, and flexible return to work options### Everybody Welcome* We value diversity and are committed to providing an inclusive and accessible recruitment process. If you require any reasonable adjustments to facilitate your participation in the recruitment process, please do not hesitate to let us know.### Need flexibility in your work?* Does this opportunity excite you but you’re not 100% sure if you meet all the requirements for the role? Or are you concerned that ‘normal’ office hours aren’t possible given your personal circumstances? Whilst we can’t accommodate every flexible working request, we’ll try to find a practical solution. So why not engage with us and find out more about this role?